Direct measurement via cyclotron resonance of the carrier effective masses in pristine diamond

We have determined effective mass parameters for ultrapure diamond by time-resolved cyclotron resonance of optically excited carriers. The transverse and longitudinal electron masses are found to be mₜ/m₀=0.280(2) and mₗ/m₀=1.56(2), where m₀ is the free-electron mass. The Luttinger parameters are extracted as γ₁=2.67(2),0.28em0exγ₂=-0.40(2), and γ₃=0.68(2), which give the light- and heavy-hole bands with considerable anisotropy and the split-off hole mass. The resonance widths indicate scattering times longer than 100 ps and carrier mobilities as high as 10⁶0.28em0excm²0.16em0exV^-10.16em0exs^-1 at 10 K.